Natural history of a visceral leishmaniasis outbreak in highland Ethiopia.

In May 2005, visceral leishmaniasis (VL) was recognized for the first time in Libo Kemken, Ethiopia, a highland region where only few cases had been reported before. We analyzed records of VL patients treated from May 25, 2005 to December 13, 2007 by the only VL treatment center in the area, maintained by Médecins Sans Frontières-Ethiopia, Operational Center Barcelona-Athens. The median age was 18 years; 77.6% were male. The overall case fatality rate was 4%, but adults 45 years or older were five times as likely to die as 5-29 year olds. Other factors associated with increased mortality included HIV infection, edema, severe malnutrition, pneumonia, tuberculosis, and vomiting. The VL epidemic expanded rapidly over a several-year period, culminating in an epidemic peak in the last third of 2005, spread over two districts, and transformed into a sustained endemic situation by 2007.

Risk factors for visceral leishmaniasis in a new epidemic site in Amhara Region, Ethiopia.

We conducted a case-control study to evaluate risk factors for visceral leishmaniasis during an epidemic in a previously unaffected district of Ethiopia. We also collected blood and bone marrow specimens from dogs in the outbreak villages. In multivariable analyses of 171 matched case-control pairs, dog ownership, sleeping under an acacia tree during the day, and habitually sleeping outside at night were associated with significantly increased risk. Specimens from 7 (3.8%) dogs were positive by immunofluorescent antibody test (IFAT) and both enzyme-linked immunosorbent assays (ELISAs), whereas Leishmania DNA was detected in 5 (2.8%) bone marrow aspirates (from 3 seropositive and 2 seronegative dogs). Insecticide-treated nets may only protect a portion of those at risk. Further research on the vectors, the role of the dog in the transmission cycle, and the effect of candidate interventions are needed to design the best strategy for control.

Kala-azar outbreak in Libo Kemkem, Ethiopia: epidemiologic and parasitologic assessment.

In May 2005, visceral leishmaniasis (VL) was recognized for the first time in Libo Kemkem, Ethiopia. In October 2005, a rapid assessment was conducted using data from 492 patients with VL treated in the district health center and a household survey of 584 residents of four villages. One subdistrict accounted for 71% of early cases, but the incidence and number of affected subdistricts increased progressively throughout 2004-2005. In household-based data, we identified 9 treated VL cases, 12 current untreated cases, and 19 deaths attributable to VL (cumulative incidence, 7%). Thirty percent of participants were leishmanin skin test positive (men, 34%; women, 26%; P = 0.06). VL was more common in men than women (9.7% versus 4.5%, P < 0.05), possibly reflecting male outdoor sleeping habits. Molecular typing in splenic aspirates showed L. infantum (six) and L. donovani (one). Local transmission resulted from multiple introductions, is now well established, and will be difficult to eradicate.